The invention concerns a large round baler with a baling chamber, at least one bale-forming device surrounding the baling chamber around its circumference, a wrapping arrangement and a wrapping material inlet opening in the enclosure of the baling chamber extending through the bale-forming device above the floor of the baling chamber.
A large round baler is known from U.S. Pat. No. 5,581,973 in whose forward region a wrapping arrangement is provided with which, for example, a net drawn from a roll can be introduced between a bale-forming roll and a deflecting roll into a baling chamber by means of a supply arrangement. The supply arrangement contains jaws that can be repositioned by a motor into which the wrapping material is clamped and on whose forward side a remaining piece hangs, that can be brought into engagement with the bale formed in the baling chamber and rotated there. The supply arrangement represents a considerable construction cost.
DE-A-34 18 681 also shows a large round baler with a wrapping arrangement attached to its forward side in which a wrapping material roll is accommodated in the forward upper corner region and two supply rolls are located between two bale-forming rolls that draw the wrapping material between them and conduct it to the baling chamber. A sharply inclined guide vane extends between the wrapping material roll and the supply rolls. These supply rolls also lead to a considerable construction cost.
According to WO-A-97/05767 a wrapping material roll is moved vertically in order to come into contact with the rotating bale which grasps and carries along the wrapping material that is also conveyed by a guide vane. The wrapping material is conducted together with the crop to be baled through a slot at the floor of the baling chamber and is inserted in this way between two layers of crop to be baled, which however, reduces the retaining force of adjoining net layers.
According to U.S. Pat. No. 5,974,764 a wrapping material roll rests on an upper of two supply or feed rolls, is brought into rotation by these during the wrapping process, and is braked relative to the rotating bale. The wrapping material is drawn between the two supply rolls and conducted to a carry-along arrangement that delivers it to an inlet opening provided at the floor of the baling chamber for the harvested crop. The supply rolls and the carry-along arrangement represent a considerable construction cost.
The problem underlying the invention is seen in the need to propose a wrapping arrangement that provides a reliable supply of wrapping material with low construction cost and construction space.
According to the present invention, there is provided an improved wrapping arrangement for delivering wrapping material into a baling chamber.
An object of the invention is to provide a wrapping arrangement which reliably delivers wrapping material to a baling chamber and is of a compact, low cost construction.
A more specific object of the invention is to provide a wrapping arrangement which includes a selectively driven roll located at an inlet for introducing wrapping material into the baling chamber, with a wrapping material supply roll being mounted for movement into engagement with the driven roll, so as to cause the wrapping material to unwrap from the supply roll and gravitate through the inlet.
In this way, no additional conveying or supply arrangement for the wrapping material is required; rather, it falls under the force of gravity into the baling chamber that is located at least partially underneath it. Two supply rolls are not required, since the wrapping material is in contact with the one supply roll, and it is carried along on the basis of this contact. The wrapping arrangement may be arranged at the forward side as well as the rear side of the large round baler, which depends on the direction of rotation of the bale or of the bale-forming device. The bale-forming device can be formed by a single wide band, by a multitude of belts, or if necessary, several sets of belts, by a bar chain conveyor or by a combination of these. Since the wrapping material inlet opening, the roll, and the wrapping material roll follow each other closely, the result is a compact configuration.
The construction arrangement can be configured with even less construction cost and space if the roll conveying the wrapping material is simultaneously a part of the bale-forming device. For example, a bale-forming roll or one or more belts draws or draw the wrapping material into the baling chamber. In this embodiment, the tension of the wrapping material upon the bale is applied by a separate brake that acts, for example, on the wrapping material roll, and if necessary, is controlled so that the wrapping material can be easily grasped by the bale and carried along at the beginning of the wrapping process. Since the carrier is adjustable, the wrapping material can be brought into contact with the bale-forming device that otherwise is still rotating only if a wrapping process is actually to be performed.
Alternatively, the roll is separated from the bale-forming device, always remains in its position, and is only driven during the wrapping operation. While it would be possible to drive the roll, for example, with an electric or hydraulic motor, since the bale-forming device or devices are driven anyway during the wrapping process, a simplification of the construction can then occur if the drive of the roll is taken from the bale-forming device. The drive so derived is then preferably geared down, so that to maintain the tension in the wrapping material, the bale rotates more rapidly than the supply of the wrapping material.
It is possible to brake the wrapping material roll in a known manner with a brake acting upon the core of the roll. It is technically simpler, however, to let the wrapping material roll with its weight rest upon a carrier, be in contact with a wall or the like. The carrier and/or the wall may be provided with a high-friction coating or a profile in order to increase the braking force.
Although the wrapping material reaches directly into the baling chamber on the basis of its own weight, the kinetic energy of the roll, however, could initially bring the wrapping material into an undesirable track. With a guide vanexe2x80x94straight or curvedxe2x80x94the wrapping material is conducted directly and safely into the wrapping material inlet opening. In place of a sheet metal guide vane, plastic or wood, or the like could also be used.
Although it has variously been proposed to make wrapping material available in pre-cut lengths, it is nevertheless considerably more effective to withdraw wrapping material for a multitude of bales from a wrapping material roll and to cut it by means of a corresponding arrangement according to the demand. Such a cutting arrangement is advantageous particularly for large round balers with a variable baling chamber since the demand there for wrapping material varies with the size of the bale.
A pressure roll loaded by a force that generally engages the wrapping material roll diametrically opposite the roll, has the result on the one hand that a certain tension is built up in the wrapping material, and on the other hand, a durable contact of the wrapping material roll on the roll is provided, particularly during rough operation on a field.
In any case, when the roll is enclosed by the wrapping material for approximately half of its circumference, the frictional force between the two is normally large enough to assure conveying on the one hand and a tension on the other hand.
A covering has the advantage that the wrapping arrangement is protected as much as possible from environmental hazards. If in addition, the pressure roll or a contact force arrangement is attached to the covering and can be repositioned together with it, the path for the exchange of a wrapping material roll can be opened simultaneously when the covering is raised or pivoted away.
A stable bearing support for the wrapping material roll can be attained easily by the provision of a contact force arrangement that acts upon the pressure roll that is in contact with the wrapping material roll on the one hand, and that is supported on the other hand, on the covering. The loading, that is, the dimensioning of the force applied to the force member, can be controlled. The force member can be loaded, for example, by a gas spring, a compression spring or extension spring, or the like.
If the force member crosses a dead center position, it can, on the one hand, thereby bring the covering into the closed position and the pressure roll in the contact force position, and on the other, hand bring both into the open position or the raised position where the position is taken up by the force stored in the force member.
If the wrapping arrangement is configured wider than the baling chamber and guide vanes or slots are provided downstream of the roll, in order to guide the wrapping material to the end faces of a bale being formed in the baling chamber, if necessary, by means of a spreader arrangement, then the bale is covered not only on its circumference, but also over its edges and partially on its end faces. In a bale formed of silage, the influence of air is thereby reduced, among other factors, whereby the quality of forage is improved.
The use of a deflector creates a free space between the bale and the side wall, into which the region of the wrapping material can escape that is to be applied later to the end faces. This deflector may be a simple plate, a shape applied to the side wall, or the like, that extends radially by at least the thickness of the wrapping material from the side wall to the interior.
The advantage of a deflector spaced away from the side wall lies in the fact that the wrapping material can be applied before its entry into the baling chamber and is carried along by the bale without any problems.